Polly Walker finds 'Sanctuary'

Polly Walker will guest star on Syfy's "Sanctuary" for two episodes next season.

The actress best known for HBO's "Rome" and Syfy's "Caprica" will play Ranna, a powerful foe who faces Helen Magnus (Amanda Tapping) after the team encounters her in the show's mid-season cliffhanger. A Syfy rep confirmed the role won't impact her "Caprica" duties.